Let’s try another source of information:
teo8976:
I would expect this to replace the three partitions that currently make up OpenSUSE with one whole partition that will contain Manjaro, which is what I want, but will this result in a bootable system?
I don’t see why not.
teo8976:
I’m particularly worried because when it shows the future layout, it includes a small “EFI system” partition, and I wonder: won’t that conflict with the existing “EFI System” partition that is currently in nvme0n1p1 which is not going to be deleted?
/dev/nvme0n1 is likely set to be the boot drive in BIOS. You may need to change its settings in order to boot on the order drive.
teo8976:
So, with the former choice I am afraid that I may end up with two conflicting “EFI system” partitions, whatever they are; and with the latter choice I am afraid that I might wipe out whatever “boot record” (or whatever it’s called) currently exists, ending up in either case with an unbootable system.
The EFI partition serves as the boot record in UEFI mode: Unified Extensible Firmware Interface - ArchWiki
teo8976:
Also I’m not sure what “manual partitioning” means, i.e. if I will have to manually define partitions in a later stage and won’t know what to do - or even worse, if it will be like “Go create the partitions by yourself in a terminal and come back when you’re done so the installation can continue”.
It’s “manual” as in “make your own partitioning”. It’s still graphical.
Difficulty: ★★★☆☆